KLM have refused to refund extra money paid for pre- booked seats on this flight where they changed our seats at the gate. They reason given was a change in aircraft from one with 2 seats either side of the aisle to one with 3. We had booked window and next to window and ended up with centre and aisle seat. My wife was most upset as she suffers from claustrophobia and prefers a window seat. This is the second time that we have found KLM totally intransigent when it comes to admitting fault and accepting to give refunds. We will never use KLM again. Buyer beware!